This invention relates to improved hair fixative compositions containing specific alpha-aminomethylene phosphonate betaine copolymers.
These resultant hair fixative compositions exhibit superior hydrocarbon tolerance, and are thus suitable for use in aerosol applications wherein hydrocarbon propellants are used, and where easy removability from the hair by shampooing is desired.
In order to be effective in aerosol hair spray formulations, the film forming, polymeric binders utilized therein as well as the films derived therefrom must meet a rigid set of requirements. The binders used in such formulations should be soluble in organic solvents and completely compatible with the propellants and solvents ordinarily employed in the aerosols; yet the films cast on the hair from such formulations should, ordinarily, be either water soluble or water dispersible in order to facilitate their easy removal from the user's hair by shampooing. As is readily visualized, this is an unusual combination of properties which is further complicated by the requirement that the binder used in such formulations be stable in the presence of, an unreactive with, the perfumes or other optional ingredients utilized in hair spray formulations.
Further, the films cast from the solutions of these binders should be flexible and yet they should have sufficient strength and elasticity to hold the hair; they should adhere well to hair so as to avoid dusting or flaking off when the hair is subjected to varying stresses; they should readily allow the hair to be recombed; they should maintain a nontacky state despite varying environmental conditions; they should be clear, transparent and glossy and should maintain this clarity on aging; they should possess good anti-static properties; and, as previously noted, they should be easily removable by the use of water and/or soap or shampoo.
Many polymeric systems have been utilized in an attempt to meet these stringent requirements. Among these are included polyvinylpyrrolidone copolymers, and N-vinyl pyrrolidone with vinylacetate, 5-5'dimethyl hydantoinformaldehyde resins and copolymers of methyl vinyl ethers and maleic acid half esters, etc. Though each of the latter systems has met at least some of the above cited requirements, none has exhibited all of these requirements to an optimum degree.
For example, carboxylated vinyl polymeric hair spray resins, particularly the carboxylated acrylate, and/or acetate based resins, have long been favored for use in aerosol hair spray formulations. Also useful are a class of carboxylated ester polymers comprising an acrylamide, an acidic film forming comonomer, and at least one polymerizable comonomer which are described in U.S. Pat. No. 3,927,199. In order to obtain optimum benefits for the use of such acidic resins, it has been required to neutralize at least a portion, and preferably most or all, of the available carboxyl functionalities with specific alkaline reagents, e.g., amines and aminohydroxy compounds, as described in, for example, U.S. Pat. Nos. 2,996,471; 3,405,084; 3,577,517, etc. Thus, alkaline reagents which are suggested for such neutralizations include ammonia, lithium hydroxide, potassium hydroxide, sodium hydroxide, mono-, di- or triethanolamine, mono-, di or tripropanolamine, morpholine, amino methyl propanol, amino methyl propanediol, hydroxy ethyl morpholine, and mixtures thereof. The purpose of this neutralization step is both to improve the water solubility or dispersibility of the resin thus permitting easy removal from the hair by merely washing with shampoo and also to affect the degree of flexibility of the resultant film when sprayed on the hair (i.e., to produce a soft film, normal film or a film suitable for "hard to hold" hair). Additionally, U.S. Pat. No. 4,192,861 teaches the use of long chain amines for the neutralization of specific polymers in aerosol hairspray systems.
One class of neutralizing agent which has been extensively used in the hair spray industry is the amines, especially 2-amino-2-methyl-1-propanol (AMP) and 2-amino-2-methyl-1,3-propanediol (AMPD). These agents are quite versatile in their utility and are used in a number of formulations marketed by a number of manufacturers.
Until recently, the majority of aerosol formulations employed halogenated hydrocarbons, particularly the chlorofluorocarbons as propellants. Such propellants were uniquely suitable for use in aerosol systems since they were compatible with polar solvents, including water. The resins employed can also have high solubility in these solvents and, thus, can be easily removed from the hair by shampooing.
Recent ecological concerns, however, have resulted in a shift away from the use of halogenated hydrocarbon propellants and cosolvents and toward the use of hydrocarbons as propellants in aerosol hair spray formulations. In such systems, the binder and any optional ingredients are dissolved in a suitable solvent, such as an alcohol, and the hydrocarbon serves as the propellant. Unfortunately, the use of these propellants produces a number of problems, some of which are due to the decrease in solubility of the binder in the solvent system as the hydrocarbon content is increased. Thus, while the carboxylated resins are soluble in the anhydrous alcohol halocarbon systems of the prior art, and are the commercially preferred resins for their holding properties, their reduced solubility in the alcohol-hydrocarbon propellant may render them unacceptable to the industry for use in aerosol systems containing high levels of hydrocarbon propellants.
A number of hydrocarbon tolerant carboxylated resins have, thus, been developed for use with hydrocarbon propellants. The development, however, presents a double-edged sword, for once the systems become sufficiently tolerant of the non-polar propellant, they ordinarily become extremely resistant to water dispersion and thus, to the removal from hair by shampooing. While this resistance to shampoo removal has been observed, to a greater or lesser extent, with all hydrocarbon tolerant carboxylated resins, some resins have been developed which lessen the problem.
One acrylate-based resin marketed by National Starch and Chemical Corporation exhibits exceptionally high hydrocarbon tolerance. The resin, a terpolymer comprising 30% (by weight) N-t-octylacrylamide, 51% isobutylmethacrylate, and 19% acrylic acid, has enjoyed wide acceptance by the industry. When neutralized by an appropriate neutralizing agent, the resin is tolerant to a high concentration of hydrocarbon and exhibits an acceptable level of shampoo removability. However, complete removal of the film from the hair can require repeated washes, making it unattractive in some applications.
Thus, there exists a need for hair spray formulations which exhibit acceptable shampoo removability as well as high tolerance of hydrocarbon propellants which are becoming increasingly important in the industry.